The Giant's Causeway is a natural rock formation. It consists of about 40,000 interlocking columns, most of which are hexagonal. The columns form huge stepping stones which slope down to the sea . It is the most popular tourist attraction in Northern Ireland. In 1986 , UNESCO declared this as a World Heritage Site.
The Giant's Causeway was actually formed by Volcanic activity about 50 million years ago. As the lava rapidly cooled , it contracted into the distinctive shapes. The Causeway is an excellent place to spot sea birds. Some rare plants also bloom here.